Method and apparatus for processing reverse transmission resources in a mobile communication system

ABSTRACT

The present invention relates to a method and apparatus for processing reverse transmission resources of a user terminal in a mobile communication system. When receiving a plurality of grants, the method and apparatus sum resources allocated by the grants, distribute the summed resources to logical channels, map the resources distributed by the logical channels and the logical channels to MAC PDUs according to the data sizes of the MAC PDUs, and allocate the resources distributed by the mapped logical channels.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for processinguplink transmission resource indicated when a terminal has receivedmultiple uplink transmission resource allocation informationssimultaneously in a mobile communication system.

2. Description of the Related Art

Mobile communication systems are developed to provide the subscriberswith voice communication services on the move. With the rapid advance oftechnologies, the mobile communication systems have evolved to supporthigh speed data communication services as well as the standard voicecommunication services.

Recently, as the next generation mobile communication system of the3^(rd) Generation Partnership Project (3GPP), Long Term Evolution (LTE)is under development. The LTE system is a technology for realizinghigh-speed packet-based communication at about 100 Mbps, aiming atcommercialization in around 2010. Regarding the commercialization of theLTE system, a discussion is being held on several schemes: one schemefor reducing the number of nodes located in a communication path bysimplifying a configuration of the network, and another scheme formaximally approximating wireless protocols to wireless channels.

Unlike voice service, data service is characterized in that the resourceis allocated according to the data amount to be transmitted and channelcondition. Accordingly, in the wireless communication system such ascellular communication system, a scheduler manages resource allocationin consideration of the resource amount, channel condition, and dataamount. This is also the case in the LTE system as one of the nextgeneration mobile communication systems such that the scheduler locatedin the base station manages and allocates the radio resource.

A description is made of the uplink data transmission procedurehereinafter. A base station transmits a grant to the terminal based onthe buffer state reported by the terminal to allocate uplink resource.The terminal assigns the resources allocated by means of the grant forindividual logical channels and generates data in match with size of theresource assigned per logical channel. The generated data aremultiplexed into MAC PDU by a MAC device such that the transceiver ofthe terminal transmits the MAC PDU on the assigned transmissionresource. This uplink data transmission procedure is defined under theassumption that the terminal receives one grant at a time point. Sinceone MAC PDU is generated by one grant, the terminal procedure is alsodesigned under the assumption that one MAC PDU is generated at a certaintime point.

SUMMARY OF THE INVENTION Problem to be Solved

As the LTE standard is evolving, discussions are being conducted on thetechniques for a terminal to receive data on multiple downlinks andtransmit data on multiple uplinks. However, there is no specifiedterminal procedure yet on how a terminal receives multiple grantssimultaneously and generates and transmits multiple MAC PDUs.

Means for Solving the Problem

In accordance with an aspect of the present invention, a method forprocessing uplink transmission resource of a user terminal in a mobilecommunication system includes aggregating, when a plurality of grantsare received, resources indicated in the grants, and dividing theaggregated resource among logical channels. Preferable mapping thelogical channels to MAC PDUs to encapsulate data on the same logicalchannel in the same MAC PDU as far as possible in consideration of sizesof the resources assigned for the logical channels and the MAC PDUs, andassigning the divided resources for the mapped logical channels.

In accordance with still another aspect of the present invention, anapparatus for processing uplink transmission resource of a user terminalin a mobile communication system includes a recipient device whichreceives a plurality of grants and a resource allocator whichaggregates, when the grants are received, resources indicated in thegrants and divides the aggregated resource among logical channels.Preferably, the resource allocator maps the logical channels to MAC PDUsto encapsulate data on the same logical channel in the same MAC PDU asfar as possible in consideration of sizes of the resources assigned forthe logical channels and the MAC PDUs and assigns the divided resourcesfor the mapped logical channels.

Advantageous Effects

The present invention allows a terminal received a plurality of grantssimultaneously to generate higher layer data to be multiplexed into aplurality of MAC PDUs while minimizing overhead.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a configuration of an LTE mobilecommunication system,

FIG. 2 is a diagram illustrating a protocol stack of an LTE mobilecommunication system,

FIG. 3 is a diagram illustrating a procedure according to an embodimentof the present invention,

FIG. 4 is a flowchart illustrating operations of a MAC device,

FIG. 5 is a flowchart illustrating operations of an RLC device receivedthe resource size from MAC layer, and

FIG. 6 is a diagram illustrating a configuration of the UE having an RLCdevice and a MAC device according to an embodiment of the presentinvention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention are described withreference to the accompanying drawings in detail. The same referencenumbers are used throughout the drawings to refer to the same or likeparts. Detailed description of well-known functions and structuresincorporated herein may be omitted to avoid obscuring the subject matterof the present invention.

The present invention proposes a method and apparatus for configuringdata to be transmitted at a terminal based on a plurality of grantsreceived simultaneously.

Prior to explaining the present invention, a description is made on theLTE mobile communication system in detail with reference to FIGS. 1 and2.

FIG. 1 is a diagram illustrating a configuration of an LTE mobilecommunication system.

Referring to FIG. 1, the LTE mobile communication system includesEvolved Radio Access Network (hereinafter, referred to as E-RAN) 110 and112) is simplified in two-node structure of evolved Node B (hereinafter,referred to as eNB or Node B) 120, 122, 124, 126, and 128 and highernode (Access Gateway or enhance Gateway GPRS Support Node, hereinafterreferred to as EGGSN) 130 and 132. The User Equipment (hereinafter,referred to as UE) 101 accesses Internet Protocol (IP) network 114 viaE-RANs 110 and 112.

The eNBs 120 to 128 corresponds to legacy node B of UMTS system. TheeNBs 120 to 128 are connected with the UE 101 via radio channel andresponsible for more complex functions as compared to the legacy node B.Since all the user traffics including real time services such as Voiceover IP (VoIP) are transmitted through shared channel, there is a needof a device for scheduling the based on the state information of the UEs101, and the eNB is responsible for this function in LTE. Each of theeNBs 120 to 128 manages a plurality cells. In order to meet therequirements of maximum data rate of 100 Mbps, LTE adopts OrthogonalFrequency Division Multiplexing (OFDM) as radio access technology inmaximum 20 MHz bandwidth. LTE also adopts Adaptive Modulation & Coding(AMC) for determining modulation scheme and channel coding ratedepending on the channel condition of the UE 101.

FIG. 2 is a diagram illustrating a protocol stack of an LTE mobilecommunication system.

Referring to FIG. 2, the protocol stack of the LTE system includesPacket Data Convergence Protocol (PDCP) 205 and 240, Radio Link Control(RLC) 210 and 235, Medium Access Control (MAC) 215 and 230, and Physical(PHY) 220 and 225. The PDCP 205 and 240 is responsible for IP headercompression/decompression, and the RLC 210 and 235 is responsible forsegmenting the PDCP Protocol Data Unit (PDU) into segments inappropriate size for Automatic Repeat Request (ARQ) operation. The MAC215 and 230 is responsible for establishing connection to a plurality ofRLC entities so as to multiplex the RLC PDUs into MAC PDUs anddemultiplex the MAC PDUs into RLC PDUs. The PHY 220 and 225 performschannel coding on the MAC PDU and modulates the MAC PDU into OFDMsymbols to transmit over radio channel or performs demodulating andchannel-decoding on the received OFDM symbols and delivers the decodeddata to the higher layer. In view of transmission, the data input to aprotocol entity is referred to as Service Data unit (SDU), and the dataoutput from the protocol entity is referred to as Protocol Data Unit(PDU).

The data requiring similar service quality are transmitted/received on alogical channel, and the logical channel corresponds to the PDCP devices205 and 240 and RLC devices 210 and 235 configured to guarantee theservice quality. Typically, one logical is configured for one service,and priority per logical channel is configured according to the requiredservice quality of the service.

In the present invention, when a plurality of grants are received, theUE 101 aggregates the resources allocated for individual grants, dividesthe aggregated resource for the individual logical channels, maps thelogical channels to the MAC PDUs according to the resources divided forthe logical channels and data size of the MAC PDU, and assigns thedivided resources for logical channels. The UE 101 also generates RLCPDUs corresponding to the resources assigned for the logical channels,multiplexes the RLC PDUs into MAC PDUs, and transmits the MAC PDUs onthe assigned resource per grant. That is, when a plurality of grants arereceived from the eNBs 120 to 128 simultaneously, the UE 101 generatesMAC PDUs in match with the sizes of resources allocated for individualgrants and transmits the MAC PDUs on the uplink transmission resourcesindicated by the grants. The higher layer data, i.e. RLC PDUs, aremultiplexed into the MAC PDUs. The present invention proposes a UEprocedure and method for allocating resources indicated by a pluralityof grants received simultaneously to corresponding logical channels,respectively.

FIG. 3 is a diagram illustrating a procedure according to an embodimentof the present invention. In the following description, MAC header andRLC header are not taken into account for convenience purpose.

Referring to FIG. 3, the UE 101 is configured with 4 logical channels305, 310, 315, and 317: logical channel 1 305 having 100 bytes of data,logical channel 2 310 having 200 bytes of data, logical channel 3 315having 1500 bytes of data, and logical channel 4 317 having 200 bytes ofdata. The logical channel 1 305 is of priority 1, the logical channel 2310 is of priority 2, the logical channel 3 315 is of priority 3, andthe logical channel 4 317 is of priority 4; and the amount of tokensaccumulated in the respective logical channels 305, 310, 315, and 317are infinite for the logical channel 1 305, 50 bytes for the logicalchannel 2 310, 50 bytes for the logical channel 3 315, and 70 bytes forthe logical channel 4 317. Here, the tokens are data to be transmittedpreferentially in the logical channels 305, 310, 315, and 317 and can beconfigured for the respective logical channels 305, 310, 315, and 317.The UE 101 receives 3 grants, the first grant 320 assigning resourcecapable of transmitting MAC PDU of 200 bytes, the second grant 325assigning resources capable of MAC PDU of 150 bytes, and the third grant330 assigning resources capable of MAC PDU of 180 bytes.

If a single grant is received, the UE divides the resource assigned asindicated by the grant among the logical channels 305, 310, 315, and317. If this is applied to the situation where multiple grants arereceived, the MAC PDU encapsulates the data originated from multiplechannels, resulting in overhead. For example, the accumulated tokensshould be assigned resource preferentially, the MAC PDU corresponding tothe first grant 320 is occupied by 100 bytes of logical channel 1 305,50 bytes of logical channel 2 310, an d50 bytes of logical channel 3315. The MAC PDU corresponding to the second grant 325 is occupied by 70bytes of logical channel 4 317 such that the tokens are assigned theresource completely, and the rest data are assigned the resource inpriority order of the logical channels 305, 310, 315, and 317 such thatthe MAC PDU corresponding to the second grant 325 is occupied by 80bytes of logical channel 2 310. The MAC PDU corresponding to the thirdgrant 330 is occupied by the rest 70 byte of logical channel 2 310 and110 bytes of logical channel 3 315.

In order to prevent each MAC PDU from carrying the data originated fromdifferent logical channels 305, 310, 315, and 317, the present inventionproposes a method in which, when multiple grants are receivedsimultaneously received, the UE aggregates the resources assigned in themultiple grants into a aggregated resource and then divides theaggregated resource among the logical channels. In the example of FIG.3, the amount of the aggregated resource is total 530 bytes obtained byaggregating 200 bytes, 130 bytes, and 180 bytes such that the UE 101divides the 530 bytes among the logical channels 305, 310, 315, and 317.The logical channel 1 305 is assigned 50 bytes, the logical channel 2310 is assigned to 200 bytes (50 bytes for tokens and 150 bytes forother data), the logical channel 3 315 is assigned 160 bytes (50 bytesfor tokens and 110 bytes for other data), and the logical channel 317 isassigned 70 bytes for tokens.

The UE 101 determines the amounts of the data of the logical channels305, 310, 315, and 317 that are to be encapsulated in MAC PDUs inconsideration of the resource amounts assigned for the logical channels305, 310, 315, and 317 and sizes of the MAC PDUs to be generated. Inorder to prevent the data of a logical channel from being encapsulatedin several MAC PDUs unnecessarily, the UE maps the data of the logicalchannels 305, 310, 315, and 315 to the MAC PDUs in descending order ofPDU size. There can be several rules for determining logical channel tobe mapped. For example, the UE 101 can map data of the logical channelassigned the greatest resource among the logical channels assigned theresource smaller than the largest MAC PDU 355 to the largest MAC PDU andrepeats this for the next largest PDUs 360 and 365. That is, the UE 101maps logical channels to the MAC PDUs 355, 360, and 365 in descendingorder of the sizes of data of the logical channels. The UE 101 also mapsthe logical channels 305, 310, 315, and 317 to the MAC PDUs 355, 360,and 365 in descending order of size of MAC PDUs. The UE 101 also mapsthe logical channels 305, 310, 315, and 317 in descending order ofremained sizes of the MAC PDUs 355, 360, and 365.

For example, the largest MAC PDU 355 is 200 bytes and greater than anyof the resources divided among the logical channels 305, 310, 315, and317 such that the data 340 of the logical channel 2 310 assigned thelargest resource is mapped to the MAC PDU 355. After mapping the data340 of the logical channel 2 310, the remained space of the MAC PDU 355becomes 0. The UE 101 selects the MAC PDU 360 largest in size with theremained space and determines the logical channel according to the samerule. As the logical channels assigned the resources smaller than theMAC PDU 360 in size among the logical channels 305, 310, 315, and 317,there are the logical channel 1 305, logical channel 3 315, and logicalchannel 4 317 of which the logical channel 1 305 is assigned the largestresource, such that the UE maps the data 345 of the logical channel 3315 to the MAC PDU 360. At this time, the remained space of the MAC PDU360 becomes 150 bytes. Afterward, the largest MAC PDU 365 is 150 bytes,and the logical channel 1 305 and logical channel 4 317 have the datasmaller than 150 bytes and are not mapped to the MAC PDUs 355, 360, and365 yet. The UE 101 maps the data 335 of the logical channel 1 350assigned the largest resource to the MAC PDU 365. Afterward, theremained space of the MAC PDU 365 is 50 bytes.

After the mapping process, the UE 101 applies the same rule to the MACPDU 365 having the largest remained space. Among the logical channels305, 310, 315, and 317 of which data are not mapped to any MAC PDU,there is no logical channel assigned the resource smaller than 50 byteof the remained space of the MAC PDU 365, such that the UE 101 maps thelogical channels assigned the resource closest to 50 bytes in size tothe remained space of the MAC PDU 365. That is, the logical channel 4317 is mapped to the remained space of MAC PDU 365 and, as aconsequence, 50 bytes of the 70-byte resource assigned to the logicalchannel 4 317 is mapped to the remained space of the MAC PDU 365 suchthat 20-byte resource is remained in the logical channel 4 317.Afterward, the UE 101 applies the same rule to the MAC PDU 360 havingthe largest remained space. Since the logical channel 4 317 having the20-byte resource which is closest to the 20-byte remained space of theMAC PDU 360, the UE 101 maps the 20 bytes of the logical channel to theremained space of the MAC PDU 360.

Through the above procedure, the UE 101 allocates one or more resourcesto the logical channels 305, 310, 315, and 317. The logical channels305, 310, 315, and 317 generates RLC PDUs using the allocated resourcesand transfers the RLC PDUs to the MAC layer. At this time, the logicalchannels 305, 310, 315, and 317 give transmission chances to the PDUs tobe retransmitted preferentially using the allocated resources andconfigures, if remained resource exists, the PDU to be initiallytransmitted in match with the remained resource size. If multipleresources are assigned to certain logical channel 305, 310, 315, and317, the UE 101 gives the transmission chances of the RLC PDUs to beretransmitted in descending order of resource sizes. The reason why thelargest resource is preferentially used for RLC PDU retransmission is toprevent the RLC PDU from being segmented because the RLC PDU greaterthan the allocated resource must be segmented. For example, if thelogical channel 4 317 has a retransmission RLC PDU of 40 bytes, the UE101 gives transmission chance of the 40-byte retransmission RLC PDU onthe resource having the largest size, i.e. 50 bytes, among the assignedresources. Next, a new RLC PDU of 10 bytes in match with the remainedresource size and another new RLC PDU of 20 bytes in match with anotherresource size are configured and then transferred to the MAC layer. TheUE 101 transmits the MAC PDUs 355, 360, and 365 to the eNBs 120 to 128.

A description is made of the operations of the elements of the UE 101according to the present invention hereinafter.

FIG. 4 is a flowchart illustrating operations of a MAC device.

Referring to FIG. 4, if a plurality of grants for initial transmissionsare received simultaneously (405), the MAC device 215 calculates amountof aggregated resource (410). The aggregated resource amount is the sumof the resources indicated in the grants. If x bytes of resource areallocated, this means that the amount of resources available fortransmitting x bytes of MAC PDUs. If a grant is transmitted for initialtransmission, this means that the grant is transmitted to allocate theresource for initial transmission of data other than HARQretransmission.

Next, the MAC device 215 of the UE 101 divides the aggregated resourceamong the logical channels (415). At this time. The MAC device 215divides the resources according to the priorities and tokens of thelogical channels. Next, the MAC device 215 of the UE 101 performslogical channel-MAC PDU mapping (420). The logical channel-MAC PDUmapping is performed in consideration of the sizes of MAC PDUs andresource amounts divided among the logical channels to determine themappings between the data generated in the logical channels and the MACPDUs. It is preferred to define the logical channel-MAC PDU mapping suchthat the data generated in the same logical channel is encapsulated inthe same MAC PDU. For example, the MAC device 215 of the UE 101 canperform the logical channel-MAC PDU mapping as follows. If a certainlogical channel is mapped to a certain MAC PDU as much as x bytes, thismeans to match the data of the logical channel as much as x bytes withthe MAC PDU.

[Example of Logical Channel-MAC PDU Mapping]

The MAC device 215 maps the logical channels to MAC PDUs in descendingorder of data sizes. The MAC device 215 also maps the logical channelsto the MAC PDUs in descending order of sizes of MAC PDUs. The MAC device215 also maps the logical channels to the MAC PDUs in descending orderof remained spaces of the MAC PDUs. That is, the logical channel towhich the largest portion of the resource is assigned among the logicalchannels of which assigned resource is equal to or less than the MAC PDUis mapped to the largest MAC PDU as much as the resource amount assignedto the logical channel. If there is no logical channel fulfilling thiscondition (that is, if the smallest resource assigned to the logicalchannels is greater than the largest MAC PDU), the logical channelassigned the resource closest to the largest PDU in size is mapped tothe MAC PDU as much as the size of the MAC PDU. Afterward, the size ofthe MAC PDU is updated by reducing as much as mapped resource size, andthe resource assigned to the logical channel is updated by reducing asmuch as the mapped resource. With the updated MAC PDU size and resourceamounts assigned to the logical channels, the above describe process isrepeated until all of the MAC PDU sizes and per-logical channel resourceamounts are updated to 0.

In the above logical channel-MAC PDU mapping scheme, one or moreresources match with a logical channel. The logical channel mapped toone MAC PDU is matched with one resource, and the logical channel mappedto multiple MAC PDUs is matched with the same number of resources as theMAC PDUs. The sizes of the resources are identical with the sizes of theresources matched with the logical channel in the mapped MAC PDU.

Next, the MAC device 215 of the UE 101 assigns the resource as much asthe size of the resource matched per logical channel (425). At thistime, a plurality of resources can be assigned for one logical channels.That is, the MAC device 215 multiplexes the RLC PDUs generated perlogical channel into MAC PDUs and transmits the MAC PDUs using theresource indicated in the grant transmitted by the eNB 120 to 128.

FIG. 5 is a flowchart illustrating operations of an RLC device receivedthe resource size from MAC layer.

Referring to FIG. 5, the RLC device 210 is assigned resource from theMAC device 215 (505). The RLC device 210 can be assigned a plurality ofresources and configure RLC PDUs to be transmitted to the MAC device 215in match with the sizes of the resources. Next, the RLC device 210determines whether a retransmission RLC PDU exists (510). Typically, theretransmission RLC PDUs have retransmission priorities determined inreverse order of sequence numbers. That is, the smaller the sequencenumber the sooner the retransmission PDU is transmitted.

If a retransmission RLC PDU exists at step 510, the RLC device 210performs step 515. Since the size of the retransmission RLC PDU isfixed, if the size of the resource is less than that of theretransmission RLC PDU, the RLC device 210 segments the retransmissionRLC PDU to fit to the resource size. It is preferred to avoid such asegmented retransmission because of the increase of overhead. In orderto avoid the segmented retransmission of the RLC PDU as far as possible,the resource allocation for retransmission RLC PDU is performed indescending order of the sizes of plural resources. The resource size isupdated by reducing as much as the amount allocated already and repeatsresource allocation to the RLC PDU having the next highestretransmission priority. For example, if the RLC device 210 is assigneda 1000 bytes of resource and a 50 bytes of resource from the MAC device215 and has the 300 byte-RLC PDU and 500-byte RLC PDU to beretransmitted, the 300-byte RLC PDU having retransmission priorityhigher than that of the 500-byte RLC PDU, the RLC device 210 assignsresources for the 300-byte retransmission RLC PDU in the 1000-byteresource largest in size and updates the size of the resource to 700bytes.

Next, the RLC device 210 determines whether there is retransmission RLCPDUs to be transmitted (520). If there is retransmission RLC PDU to betransmitted, the RLC device 210 assigns resource to the retransmissionRLC PDU having the next highest retransmission priority in the nextlargest resource (525). For example, since the next largest resource isthe 700-byte resource remained after assigning 300 bytes from the 1000byte-resource, the RLC device 210 assigns resource from the 500-byteretransmission RLC PDU in the 700-byte resource. Afterward, the RLCdevice 210 returns the procedure to step 520 to determine whether thereis retransmission RLC PDU to be transmitted. If there is furtherretransmission RLC PDU to be transmitted, the RLC device 210 repeatsstep 520 to 525.

Finally, if there is no further retransmission RLC PDU at step 510 or520, the RLC device 210 performs generates initial transmission RLC PDUsin match with the remained resources (530). For example, there are200-byte resources remained after assigning 800 bytes from the 1000-byteresource for retransmission RLC PDU and the 50-byte resource which isremained without being assigned for retransmission RLC PDU. The RLCdevice 210 generates RLC PDUs of 200 bytes and 50 bytes for initialtransmission. Afterward, the RLC device 210 transfers the retransmissionRLC PDUs and initial transmission RLC PDUs to the MAC device 215 (535).

As described above, when there is retransmission RLC PDU to betransmitted, the RLC device 210 assigns resource for the retransmissionRLC PDU in the largest resource to avoid segmentation of theretransmission RLC PDU. Another approach to prevent the retransmissionRLC PDU from being segmented is to assign the resource closest to theresource in size among the resources larger than the retransmission RLCPDU. After updating the resource by reducing as much as assignedalready, the RLC device 210 assigns the resource to the retransmissionRLC PDU having the next highest priority in the same manner until all ofthe retransmission RLC PDUs are assigned corresponding resource or theremained resource amount becomes 0 and, if there is remained resource,generate new RLC PDUs to be transmitted initially with the remainedresource.

For example, in a case where 100-byte, 200-byte, and 300-byte resourcesare allocated by the MAC device 215 while there are 150-byte, 250-byte,and 100-byte RLC PDUs to be retransmitted in sequential priority order,the RLC device 210 assigns transmission resource for the retransmission105-byte RLC PDU having the highest priority from the 200-byte closestto the 150-byte RLC PDU in size among the resources larger than thecorresponding PDU. Next, the RLC device 210 assigns transmissionresource for the 250-byte retransmission RLC PDU having the next highestpriority from the 300-byte resource closest to the 250-byteretransmission RLC PDU in size among the resources larger than thecorresponding PDU. Likewise, the RLC device 210 assigns transmissionresource for the 100-byte retransmission RLC PDU having the next highestpriority from the 100-byte resource closest to the 100-byteretransmission RLC PDU in size among the resources larger than thecorresponding PDU. As a result of this resource assignment, two 50-byteresources are remained such that the RLC device 210 configures initialtransmission RLC PDUs in match with the size of remained resources.

A description is made of the configuration of UE 101 hereinafter. FIG. 6is a diagram illustrating a configuration of the UE having an RLC deviceand a MAC device according to an embodiment of the present invention.

Referring to FIG. 6, the MAC device 210 includes amultiplexer/demultiplexer 610 and a resource allocator 615 and connectsto a transceiver 605. The transceiver 605 is the device for processingthe signals transmitted and received through LTE radio channel, thetransceiver 605 delivering MAC PDUs received on the radio channel to themultiplexer/demultiplexer 610 and providing grant information to theresource allocator 615. The multiplexer/demultiplexer 610 multiplexesthe RLC PDUs from the RLC device 620 into a MAC PDU and sends themultiplexed MAC PDU to the transceiver 605 and demultiplexes the MAC PDUfrom the transceiver 605 into RLC PDUs and sends the demultiplexed RLCPDUs to the RLC device 620. The resource allocator 615 analyzes thegrant received from the transceiver 605 to check the total amount of theallocated resources. In case that a plurality of grants are received,the resource allocator 615 calculates the total amount of the resourceby aggregating the resources indicated in the individual grants, i.e.the aggregated resource. The resource allocator 615 divides theaggregated resource among the logical channels in consideration of thetotal amount of the resource, data amounts saved for the respectivelogical channels, priorities and accumulated tokens of the logicalchannels. The resource allocator 615 also determines the sizes of theresources to be assigned for logical channels by mapping the MAC PDUs tobe generated by the grants and the logical channels. As aforementioned,when a logical channel is mapped to multiple MAC PDUs, multipleresources are assigned for the logical channels. The resource allocator615 notifies a transmission controller 635 of the RLC device of theassigned resources.

The RLC device 620 includes a transmission buffer 625, a framing device630, and a transmission controller 635. The transmission controller 635assigns resource for RLC PDUs to be retransmitted in consideration ofthe resource size informed by the resource allocator 615 and generatesinitial transmission RLC PDUs to remained resources. The transmissionbuffer 625 buffers the data delivered from higher layers. Thetransmission buffer 625 also buffers the RLC PDUs to be retransmitted.The framing device 630 is the device for framing the higher layer datainto RLC PDUs so as to segment or concatenate the higher layer data intoappropriate sizes and attach a predetermined header. The framing device630 also may re-segment the RLC PDUs to be retransmitted intoappropriate sizes. By adding predetermined header information, therecipient device can recover the original RLC PDUs from the segmentedRLC PDUs.

Although the description has been made with reference to particularembodiments, the present invention can be implemented with variousmodification without departing from the scope of the present invention.Thus, the present invention is not limited to the particular embodimentsdisclosed but will include the following claims and their equivalents.

What is claimed is:
 1. A method of a terminal in a mobile communicationsystem, comprising: determining, based on reception of a plurality ofgrants for a transmission time interval (TTI) from a base station, totransmit multiple media access control (MAC) protocol data units (PDUs)in the TTI; aggregating resources indicated in the plurality of grants,each of the grants including uplink scheduling information; andallocating the aggregated resources to at least one of logical channelsin decreasing priority order based on information associated with eachresource amount to be allocated preferentially to each of the logicalchannels.
 2. The method of claim 1, further comprising: mapping thelogical channels to the MAC PDUs based on resources allocated to each ofthe logical channels and sizes of the MAC PDUs.
 3. The method of claim2, wherein the mapping of the logical channels to the MAC PDUs comprisesmapping the logical channels to the MAC PDUs in decreasing order of thesizes of the MAC PDUs.
 4. The method of claim 3, wherein the mapping ofthe logical channels to the MAC PDUs comprises mapping the logicalchannels to the MAC PDUs in decreasing order of the resources allocatedto each of the logical channels.
 5. The method of claim 2, furthercomprising: configuring radio link control (RLC) PDUs according to theresources allocated to the logical channels.
 6. The method of claim 5,further comprising: allocating retransmission RLC PDUs prior to newtransmission RLC PDUs.
 7. The method of claim 1, further comprising:allocating, if any resources remain, the remained resources to the atleast one of the logical channels in decreasing priority order.
 8. Aterminal in a mobile communication system, comprising: a receiverconfigured to receive a plurality of grants from a base station; and aresource allocator configured to: determine, based on reception of aplurality of grants for a transmission time interval (TTI) from a basestation, to transmit multiple media access control (MAC) protocol dataunits (PDUs) in the TTI, aggregate resources indicated in the pluralityof grants, each of the grants including uplink scheduling information,and allocate the aggregated resources to at least one of logicalchannels in decreasing priority order based on first informationassociated with each resource amount to be allocated preferentially toeach of the logical channel.
 9. The terminal of claim 8, wherein theresource allocator is configured to map the logical channels to the MACPDUs based on resources allocated to each of the logical channels andsizes of the MAC PDUs.
 10. The terminal of claim 9, wherein the resourceallocator is further configured to map the logical channels to the MACPDUs in decreasing order of the sizes of the MAC PDUs.
 11. The terminalof claim 10, wherein the resource allocator is further configured to mapthe logical channels to the MAC PDUs in decreasing order of theresources allocated to each of the logical channels.
 12. The terminal ofclaim 9, further comprising: a radio link control (RLC) deviceconfigured to configure RLC PDUs according to the resources allocated tothe logical channels.
 13. The terminal of claim 12, wherein the RLCdevice is configured to allocate retransmission RLC PDUs prior to newtransmission RLC PDUs.
 14. The terminal of claim 8, wherein the resourceallocator is configured to allocate, if any resources remained, theremained resources to the at least one of the logical channels indecreasing priority order.